Catheter Handle

ABSTRACT

A medical instrument includes first and second knobs. The first knob is fitted on a handle of the medical instrument, and is movable along a longitudinal axis of the medical instrument to control a deflection of a medical device coupled to a distal end of the medical instrument relative to the longitudinal axis. The second knob is fitted on the handle of the medical instrument, and is movable along the longitudinal axis to control a shape of the medical device.

FIELD OF THE INVENTION

The present invention relates generally to catheters, and particularlyto methods and systems for controlling deflection and shape of ballooncatheters.

BACKGROUND OF THE INVENTION

Balloon catheters may be used in various medical procedures, such as incardiac ablation. The balloon catheter is typically controlled remotelyby a physician. Method and devices for controlling the operation ofballoon catheters are known in the art.

For example, U.S. Pat. No. 9,579,448 describes a medical device for thetreatment and irrigation of a sinus opening is described. The deviceallows for single-handed operation to access, dilate and irrigate asinus opening. The device includes a sinus guide catheter, a guidingelement, a balloon dilation catheter, a balloon catheter movementmechanism and a guiding element movement mechanism.

U.S. Pat. No. 6,221,070 describes a steerable ablation catheter systemsuitable for radiofrequency ablation of intra-cardiac tissue thatcomprises two parts: a disposable catheter shaft with a deflectable tipat the distal end of the shaft, and a handle with steering mechanisms.

SUMMARY OF THE INVENTION

An embodiment of the present invention that is described herein providesa medical instrument including first and second knobs. The first knob isfitted on a handle of the medical instrument, and is movable along alongitudinal axis of the medical instrument to control a deflection of amedical device coupled to a distal end of the medical instrumentrelative to the longitudinal axis. The second knob is fitted on thehandle of the medical instrument, and is movable along the longitudinalaxis to control a shape of the medical device.

In some embodiments, the first knob is configured to apply first andsecond levels of deflection of the medical device relative to thelongitudinal axis of the medical instrument by being set at respectiveselected first and second positions along the longitudinal axis of themedical instrument. In other embodiments, the second knob is configuredto set the medical device to first and second shapes by being set atrespective selected first and second positions along the longitudinalaxis of the medical instrument. In yet other embodiments, the first andsecond knobs are configured to operate independently of one another.

In an embodiment, at least one of the first and second knobs is movable,within a continuous range, along the longitudinal axis. In anotherembodiment, the handle includes a grip located in proximity to the firstand second knobs, such that both the first and second knobs areaccessible by one or more fingers of an operator hand that holds thegrip. In yet another embodiment, the medical device is configured to beapplied in a medical procedure selected from a list consisting ofelectrophysiology, ablation, sinuplasty, surgery, endoscopy,angioplasty, otolaryngology and neurology.

In some embodiments, the medical device includes an inflatable ballooncatheter having an internal volume configured to receive inflationfluid. In other embodiments, the second knob is configured, when movedin a first direction along the longitudinal axis, to allow an inflationof the internal volume of the balloon catheter, and when moved in asecond direction along the longitudinal axis, to deflate the ballooncatheter by elongating the balloon and forcing the inflation fluid outof the internal volume. In yet other embodiments, the inflatable ballooncatheter includes one or more electrodes coupled to an outer surface ofthe inflatable balloon catheter.

In an embodiment, the medical device includes at least one of electrodesand sensors coupled to the medical device at predefined positions, andat least one of the first and second knobs includes one or more markersindicative of the respective positions of the at least one of electrodesand sensors. In another embodiment, each of the one or more markersincludes a respective number of an electrode or a sensor of the at leastone of electrodes and sensors.

There is additionally provided, in accordance with an embodiment of thepresent invention, a method including inserting a medical device coupledto a distal end of a medical instrument into a patient organ. Adeflection of the medical device, relative to a longitudinal axis of themedical instrument, is controlled by moving a first knob, which isfitted on a handle of the medical instrument, along the longitudinalaxis. A shape of the medical device is controlled by moving a secondknob, which is fitted on the handle of the medical instrument, along thelongitudinal axis of the medical instrument. A medical procedure isconducted in the patient organ using the medical device.

The present invention will be more fully understood from the followingdetailed description of the embodiments thereof, taken together with thedrawings in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic, pictorial illustration of a catheter-basedtracking and ablation system, in accordance with an embodiment of thepresent invention;

FIGS. 2A and 2B are schematic, pictorial illustrations of a ballooncatheter control handle, in accordance with an embodiment of the presentinvention; and

FIG. 3 is a flow chart that schematically illustrates a method forconducting a medical procedure using a balloon catheter, in accordancewith an embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS Overview

Catheters are used, for example, in various interventional cardiologyprocedures, such as in treating arrhythmia, by ablating the heart tissueso as to form a lesion that blocks electrical conduction along a path ofthe heart tissue. A catheter used for ablation may comprise aninflatable balloon assembly having an array of devices, such as ablationelectrodes, mounted on an outer surface of the balloon assembly. Acatheter of this sort is referred to herein as a balloon catheter.

Embodiments of the present invention that are described hereinbelowprovide improved techniques for controlling the operations of inflationand deflection of a balloon catheter.

During an ablation procedure, a physician typically starts with adeflated balloon for navigating the catheter to a target location in apatient heart. At the target location, the physician inflates theballoon so as to make physical contact between at least some of theablation electrodes and heart tissue at the target location. In somecases, the physician may have to deflect the balloon assembly relativeto the longitudinal axis of the catheter, so as to better reach thetarget tissue and/or improve the physical contact with the tissue.

In some embodiments, the catheter comprises a handle, which is coupledto the catheter proximal end, and which is configured to control theballoon assembly at the catheter distal end. At least first and secondknobs are fitted on the handle and are movable along the longitudinalaxis of the catheter. The first knob is configured to control adeflection of the balloon assembly relative to the longitudinal axis,and the second knob is configured to control the shape of the ballooncatheter by elongating the balloon, thus collapsing it and forcing outinflation fluid through existing holes in the balloon. In someembodiments, the first and second knobs are configured to operateindependently of one another, such that the physician may inflate ordeflate the balloon assembly before or after deflecting the distal endof the catheter, or in any other suitable operational sequence.

In some embodiments, the level of inflation of the balloon assembly andthe level of deflection of the distal end are each controllable in acontinuous manner. In an exemplary sequence, the physician may deflectthe distal end to its maximal deflection level after inflating a portion(e.g., half) of the internal volume of the balloon assembly, andsubsequently, the physician inflates the balloon assembly to a fullyinflated position.

The disclosed techniques improve the patient safety by providing thephysician with easy control of the inflation and deflection operationsof the balloon catheter using a single finger. When using the disclosedtechniques, the physician can focus his or her attention on the essenceof the procedure rather than on the technical manipulation of theballoon catheter.

Furthermore, the disclosed techniques may increase the success rate ofablation procedures by enabling accurate positioning of the ablationelectrodes at the target locations of the tissue.

System Description

FIG. 1 is a schematic, pictorial illustration of a catheterizationsystem 20, in accordance with an embodiment of the present Invention.System 20 comprises a medical instrument, such as a balloon catheter 22,and a control console 24. In the embodiment described herein, catheter22 may be used for any suitable therapeutic and/or diagnostic purposes,such as for ablating tissue or sensing electrophysiological (EP) signalsfrom a heart 21 of a patient 28.

In some embodiments, console 24 comprises a processor 34 having suitablefront end and interface circuits for receiving signals from catheter 22,and for controlling other components of system 20.

In some embodiments, processor 34 typically comprises a general-purposeprocessor, which is programmed in software to carry out the functionsdescribed herein. The software may be downloaded to the computer inelectronic form, over a network, for example, or it may, alternativelyor additionally, be provided and/or stored on non-transitory tangiblemedia, such as magnetic, optical, or electronic memory.

In some embodiments, console 24 further comprises a memory 38 and adisplay 46, which is configured to display data, such as an image 44 ofat least part of heart 21. In some embodiments, image 44 may be acquiredusing any suitable anatomical imaging system.

Reference is now made to an inset 23. A physician 30 inserts a shaft 25through the vascular system of patient 28 lying on a table 29. In someembodiments, catheter 22 comprises a balloon assembly 40 fitted at thedistal end of shaft 25. During the insertion of shaft 25, balloonassembly 40 is maintained in a collapsed position by a sheath (notshown). By containing assembly 40 in the collapsed position, the sheathalso serves to minimize vascular trauma along the way to a targetlocation. In some embodiments, physician 30 navigates balloon assembly40 to the target location, such as a left atrium or another cavity ofheart 21, by manipulating shaft 25 using control handles 32 and 33coupled to the proximal end of catheter 22.

In some embodiments, physician applies handle 32 for controlling thenavigation of shaft 25 and for manipulating the distal end of catheter22, e.g., so as to make contact between assembly 40 and tissue of heart21, as will be described in detail in FIG. 2B below. Once the distal endof shaft 25 has reached the target location, physician 30 extractsassembly 40 out of the sheath, referred to herein as an “unextendedposition,” and allows a pump, such as an irrigation pump (not shown), toinflate balloon assembly 40 to an expanded position, as will also bedescribed in detail in FIG. 2B below.

In some embodiments, the proximal end of catheter 22 is connected tointerface circuitry in processor 34, and is described in further detailin FIGS. 2A and 2B below.

In some embodiments, the position of distal-end assembly 40 in the heartcavity is typically measured using position sensing techniques. Thismethod of position sensing is implemented, for example, in the CARTO™system, produced by Biosense Webster Inc. (Irvine, Calif.) and isdescribed in detail in U.S. Pat. Nos. 5,391,199, 6,690,963, 6,484,118,6,239,724, 6,618,612 and 6,332,089, in PCT Patent Publication WO96/05768, and in U.S. Patent Application Publications 2002/0065455 A1,2003/0120150 A1 and 2004/0068178 A1, whose disclosures are allincorporated herein by reference.

In some embodiments, console 24 comprises a driver circuit 41, whichdrives magnetic field generators 36 placed at known positions externalto patient 28, e.g., below the patient torso.

In some embodiments, when the distal end of catheter 22 is positioned inthe target location (e.g., the cavity of heart 21), physician 30extracts balloon assembly 40 out of the sheath and applies handle 32 tomanipulate assembly such that an outer surface of assembly 40 makes aphysical contact with tissue of the cavity.

In some embodiments, balloon assembly 40 comprises an inflatable balloon(not shown) made from polyethylene terephthalate (PET), polyurethane,polyamide, or any other suitable flexible material. The inflatableballoon is configured to receive inflation fluid into an internal volumeof balloon assembly 40.

In some embodiments, physician 30 may apply handle 32 to bring balloonassembly 40 to a non-extended position and allow it to fill with theinflation fluid, or by using any other suitable inflation technique. Thelevel of inflation determines the shape of assembly 40 so that, in someembodiments, handle 32 is configured to control the level of inflationas will be described in detail in FIG. 2B, as well as in the methoddescribed in FIG. 3 below.

In some embodiments, handle 32 is further configured to control adeflection level of balloon assembly 40 relative to a longitudinal axisof catheter 22. In case the contact between assembly 40 and the hearttissue is insufficiently firm, physician 30 may apply handle 32 todeflect assembly 40 so as to make improved contact between assembly 40and the heart tissue.

In some embodiments, physician 30 may determine the levels of inflationand deflection of assembly 40 by setting one or more knobs (typicallytwo knobs as shown in FIGS. 2A and 2B) of handle 32 to a selectedposition.

In some embodiments, the operations of inflation and deflection may becarried out separately (e.g., an inflation operation followed by adeflection operation), in parallel (e.g., setting both the shape of theballoon and the deflection level simultaneously), alternately (e.g., bysetting an initial shape followed by initial deflection, andsubsequently inflating (or deflating) assembly 40 to a final shape anddeflecting again so as to better reach the target tissue and achieve theintended level of physical contact between assembly 40 and the hearttissue. In other embodiments, any other suitable sequence of operations,or a different combination of the operations described above, may beused.

In some embodiments, assembly 40 further comprises one or moreelectrodes 48 (ten electrodes in the example of FIG. 1), coupled to theouter surface of assembly 40 and configured to exchange electricalsignals with the proximal end of catheter 22 and to conduct theelectrical signals to or from the tissue of heart 21. During a medicalprocedure, such as cardiac EP mapping or tissue ablation, electrodes 48are brought into contact with the tissue of heart 21, so as to senseelectrical signals originated therefrom, or to apply ablation signalsfor ablating the tissue as described above.

In the context of the present disclosure, the term “electrodes” refersto sensing electrodes or to ablating electrodes configured to senseelectrical signals from heart 21 or to ablate tissue of heart 21,respectively.

The configuration of system 20 shown in FIG. 1 is an exampleconfiguration, which is chosen purely for the sake of conceptualclarity. In alternative embodiments, any other suitable configurationcan also be used. For example, the size and shape of distal-end assembly40, and additional components, such as thermocouples and irrigationholes may be implemented in any suitable location in assembly 40.

Controlling the Shape and Deflection of the Balloon Assembly

FIG. 2A is a schematic, pictorial illustration of handle 32 in a homeposition, in accordance with an embodiment of the present invention.

In some embodiments, handle 32 comprises a grip 45, typically located atthe proximal end of handle 32 and held by a hand of physician 30. In theexample of FIG. 1 physician 30 holds handle 32 in one hand, and uses theother hand located near the end of the sheath to further control themovement. We generally assume that the physician holds the catheter byhis or her right hand, but a left-handed person may hold the handle bythe left hand.

In some embodiments, handle 32 comprises a deflection knob 50, which isconfigured to move along a longitudinal axis (shown in FIG. 2B) ofcatheter 22 so as to control the deflection of assembly 40 relative tothe longitudinal axis of catheter 22. In some embodiments, physician 30may use the thumb (or one or more other fingers) of his or her righthand (i.e., the same hand holding the catheter handle) to advance knob50, so as to deflect assembly 40 relative to the longitudinal axis ofcatheter 22.

In similar embodiments, physician 30 may use one or more fingers of hisor her right hand to retract knob 50, so as to align assembly 40relative to the longitudinal axis of catheter 22.

In some embodiments, handle 32 comprises a shape-control knob 60, whichis configured to control the shape of balloon assembly 40. As describedin FIG. 1 above, physician 30 may apply control knob 60 to control theshape of assembly 40 by elongating the balloon of assembly 40, thuscollapsing it and forcing out the inflation fluid through existing holesin the balloon.

In some embodiments, physician 30 may control the shape of assembly 40by moving shape-control knob 60 using one or more fingers in a similarmanner as described above for deflection knob 50.

Note that both deflection knob 50 and shape-control knob 60 are locatedin close proximity to grip 45, such that when physician holds grip 45,for example, using his or her right hand, each of deflection knob 50 andcontrol knob 60 is accessible by one or more fingers (e.g., the thumb)of the same hand that holds grip 45.

In the example of FIG. 2A, deflection knob 50 and shape-control knob 60are fully retracted so that assembly 40 is not inflated and issubstantially aligned with the longitudinal axis of catheter 22. Thisposition is referred to herein as a “home position,” which is thetypical position of assembly 40 during introduction through the sheath.

FIG. 2B is a schematic, pictorial illustration of handle 32 in anextended position, in accordance with an embodiment of the presentinvention. In the context of the present disclosure and in the claims,the terms “expanded position”, “extended position” and “inflatedposition” are used interchangeably and refer to a position in whichballoon assembly 40 is fully (or partially) inflated with the inflationfluid.

In some embodiments, physician 30 may move deflection knob 50 over adeflection setting range 52 along axis 49 of handle 32, in directionsrepresented by a two-way arrow 54, so as to set the degree of deflectionof assembly 40 relative to axis 49. For example, physician 30 may movedeflection knob 50 to one end of deflection setting range (e.g., thedistal end), so as to obtain the maximal level of deflection of assembly40, and may similarly align assembly 40 with axis 49 by settingdeflection knob 50 at the opposite (e.g., proximal) end of deflectionsetting range 52. In some embodiments, the handle comprises mechanicalstoppers at the ends of deflection setting range 52.

In the example of FIG. 2A, deflection knob 50 is fully retracted to theproximal end of deflection setting range 52, so that it makes contactwith the mechanical stopper, such as the distal end of grip 45 that isconfigured to limit the motion of knob 50 within deflection settingrange 52.

In the example of FIG. 2B, knob 50 is fully advanced to the distal endof deflection setting range 52, so that it makes contact with themechanical stopper that prevents further deflection of assembly 40.

In some embodiments, shape-control knob 60 is limited to move within apredefined range, referred to herein as a shape setting range 62 having,for example, a similar configuration and operational mode describedabove for the deflection setting range of deflection knob 50.

In some embodiments, physician may advance shape-control knob 60 alongshape setting range 62, so as to extract the distal end of the balloonof assembly 40 to the unextended position, and to allow the irrigationpump to inflate the balloon with inflation fluid (not shown). In theseembodiments, by sliding shape-control knob 60 forward to a certainposition, physician 30 sets the shape of balloon assembly 40.

In an embodiment, physician 30 may advance shape-control knob 60 alongaxis 49 in directions represented by a two-way arrow 64, to the distalend of shape setting range 62 so as to set assembly 40 in an “inflatedposition.”

Similarly, physician 30 may retract shape-control knob 60 to theproximal end of shape setting range 62, referred to herein as “homeposition” of knob 60 as shown in FIG. 2A. In the home position of knob60, the balloon of assembly 40 is elongated so that the inflation fluidis forced out of the internal volume of assembly 40, e.g., into the bodyof patient 28, or into a reservoir (not shown) of system 20.

Note that, when deflection knob 50 and shape-control knob 60 are, each,positioned at the distal end of respective ranges 52 and 62, assembly 40is fully deflected relative to axis 49 and is fully inflated. Thisextended position typically assists physician 30 in manipulatingassembly 40 to make the intended contact of the balloon catheter withthe target tissue of heart 21.

In some embodiments, deflection knob 50 can be positioned at any pointalong deflection setting range 52. In alternative embodiments,deflection knob 50 can be set only at one or more predefined positionsalong the range.

In some embodiments, deflection knob 50 and shape-control knob 60 may befitted on the distal end of grip 45 as shown in FIG. 2A, or may becoupled to handle 32 using any other suitable configuration and couplingtechnique. For example, deflection knob 50 and shape-control knob 60 maybe fitted on handle 32 side-by-side instead of after one another alongaxis 49.

In some embodiments, shape-control at least one of knobs 50 and 60 mayhave one or more numbers marked on the surface, as shown in FIGS. 2A and2B. In an embodiment, each number indicates a position of a respectiveelectrode 48 on the outer surface of assembly 40, so as to assistphysician 30 in knowing the orientation of balloon assembly 40 in heart21, without relying on a mapping system or X-ray visualization. In otherembodiments, the numbers, or any other suitable marker, may be used toindicate the position of any device, such as one or more electrodesand/or sensors coupled to the outer surface of assembly 40.

In the example of FIGS. 2A and 2B, deflection knob 50 and shape-controlknob 60 are movable along respective linear ranges (e.g., deflectionsetting range 52 and shape setting range 62) along axis 49. Inalternative embodiments, at least one of these ranges may have anon-linear shape, such as a curved shape or any other suitable shape.For example, deflection knob 50 may control the deflection of assembly40 by rotating, rather than by moving in a linear range.

FIG. 3 is a flow chart that schematically illustrates a method forconducting a medical procedure using balloon catheter 22, in accordancewith an embodiment of the present invention. The method begins at acatheter insertion step 100, with physician 30 inserting catheter 22into the body of patient 28 and navigating assembly 40 to the cavity ofheart 21. At a balloon inflation step 102, physician 30 advancesshape-control knob 60 towards the distal end of shape setting range 62,unextending balloon and then inflates assembly 40 with the inflationfluid using the irrigation pump.

At a balloon deflection step 104, physician 30 advances deflection knob50 towards the distal end of deflection setting range 52, so as todeflect assembly 40 relative to axis 49. In some embodiments, physician30 may check, after concluding each of steps 102 and 104, whetherassembly 40 makes the intended contact with the tissue of heart 21. Incase the intended contact is not obtained, physician 30 may repeat step102 and/or step 104 until the intended contact between assembly 40 andthe tissue is obtained.

After bringing assembly 40 into the intended contact with the tissue,physician 30 may carry out the medical procedure, such as ablating thetissue of heart 21, at a treatment step 106. In some embodiments, themedical procedure may involve diagnostics, such as sensing of EP signalsfrom the tissue of heart 21.

After concluding the medical procedure, physician 30 may align assembly40 with axis 49 by retracting deflection knob 50 to the proximal end ofdeflection setting range 52, at a distal end alignment step 108.

At a deflating step 110, physician retracts shape-control knob 60 to theproximal end of shape setting range 62, so as to force the fluid out ofthe internal volume of assembly 40, thereby to set assembly 40 in theunextended position. After concluding step 110, handle 32 is set at homeposition as shown in FIG. 2A above.

In some embodiments, physician 30 may change the order between steps 102and 104, or may apply any suitable sequence as described in FIG. 2Babove, so as to obtain, before applying the medical procedure at step106, the intended contact between assembly 40 and the tissue of heart21.

In some embodiments, after concluding the medical procedure at step 106,physician 30 may change the order between steps 108 and 110, or mayapply any other suitable sequence, so as to set handle 32 at homeposition.

In some embodiments, after inflating balloon assembly 40 at step 100physician 30 may extract balloon assembly 40 out of the sheath, asdescribed in FIG. 1 above. In some embodiments, after concluding step110, assembly 40 is in the unextended position and aligned with axis 49.At this stage, physician 30 may insert assembly 40 into the sheath,thereby setting assembly 40 at a collapsed position.

At a retraction step 112, physician retracts catheter 22 so as toextract assembly 40 out of the body of patient 28. Step 112 concludesthe method of FIG. 3.

Although the embodiments described herein mainly address cardiacarrhythmia, the methods and systems described herein can also be used inother applications, such as in electrophysiology, ablation of tissue,sinuplasty, surgery, endoscopy, angioplasty, otolaryngology andneurology.

It will thus be appreciated that the embodiments described above arecited by way of example, and that the present invention is not limitedto what has been particularly shown and described hereinabove. Rather,the scope of the present invention includes both combinations andsub-combinations of the various features described hereinabove, as wellas variations and modifications thereof which would occur to personsskilled in the art upon reading the foregoing description and which arenot disclosed in the prior art. Documents incorporated by reference inthe present patent application are to be considered an integral part ofthe application except that to the extent any terms are defined in theseincorporated documents in a manner that conflicts with the definitionsmade explicitly or implicitly in the present specification, only thedefinitions in the present specification should be considered.

1-12. (canceled)
 13. A method, comprising: inserting a medical devicecoupled to a distal end of a medical instrument into a patient organ,the medical device comprises at least one of electrodes and sensorscoupled to the medical device at predefined positions; controlling adeflection of the medical device, relative to a longitudinal axis of themedical instrument, by moving a first knob, which is fitted on a handleof the medical instrument, along the longitudinal axis; controlling ashape of the medical device by moving a second knob, which is fitted onthe handle of the medical instrument, along the longitudinal axis of themedical instrument, the second knobs comprises one or more markersindicative of the respective positions of the at least one of electrodesand sensors; and conducting a medical procedure in the patient organusing the medical device.
 14. The method according to claim 13, whereincontrolling the deflection comprises applying first and second levels ofdeflection of the medical device relative to the longitudinal axis ofthe medical instrument by setting the first knob at respective selectedfirst and second positions along the longitudinal axis of the medicalinstrument.
 15. The method according to claim 13, wherein controllingthe shape comprises setting the medical device to first and secondshapes by setting the second knob at respective selected first andsecond positions along the longitudinal axis of the medical instrument.16. The method according to claim 13, wherein controlling the deflectionand controlling the shape comprises operating the first and second knobsindependently of one another.
 17. The method according to claim 13,wherein controlling the deflection and controlling the shape comprisesmoving at least one of the first and second knobs, within a continuousrange, along the longitudinal axis.
 18. The method according to claim13, wherein the handle comprises a grip located in proximity to thefirst and second knobs, such that both the first and second knobs areaccessible by one or more fingers of an operator hand that holds thegrip.
 19. The method according to claim 13, wherein conducting themedical procedure comprises applying the medical device in a medicalprocedure selected from a list consisting of electrophysiology,ablation, sinuplasty, surgery, endoscopy, angioplasty, otolaryngologyand neurology.
 20. The method according to claim 13, wherein insertingthe medical device comprises inserting an inflatable balloon catheterhaving an internal volume for receiving inflation fluid.
 21. The methodaccording to claim 20, wherein controlling the shape comprises movingthe second knob in a first direction along the longitudinal axis so asto allow an inflation of the internal volume of the balloon catheter,and moving the second knob in a second direction along the longitudinalaxis for deflating the balloon catheter by elongating the ballooncatheter and forcing the inflation fluid out of the internal volume. 22.The method according to claim 20, wherein the inflatable ballooncatheter comprises multiple electrodes coupled to an outer surface ofthe inflatable balloon catheter.
 23. (canceled)
 24. The method accordingto claim 23, wherein each of the one or more markers comprises arespective number of an electrode or a sensor of the at least one ofelectrodes and sensors.